On Thu, 26 Jul 2007 15:36:24 -0400 Will Woods <[EMAIL PROTECTED]> wrote:
> On Thu, 2007-07-26 at 11:48 -0700, Andrew Morton wrote: > > On Thu, 26 Jul 2007 13:40:19 -0400 Neil Horman <[EMAIL PROTECTED]> wrote: > > > > > Currently, core dumps can be redirected to a pipe by placing the > > > following string template in /proc/sys/kernel/core_pattern: > > > |<path/to/application> > > > This patch extends this ability, allowing the core_pattern to contain > > > arguments > > > to be passed as an argv array to the userspace helper application. It > > > also add > > > a format specifier, %c, which allows the RLIM_CORE value of the crashing > > > application to be passed on the command line, since RLIMIT_CORE is > > > reduced to > > > zero when execing the userspace helper > > > > This all seems to be getting a bit nutty. Who needs this feature > > and what will they do with it, etc? > > We're using it for doing a system-wide crash dump handler. Currently > Ubuntu's using it with their Apport tool[1] for this purpose; I'm > adapting that for Fedora. Can you please copy the relevant Ubuntu people on the patches then? It would be valuable to get their input on the proposal. > The Ubuntu approach requires a kernel patch that adds a bunch of process > information (process pid, RLIMIT_CORE, etc) to the environment of the > crash handler[2]. Most of that information can instead be parsed out of > the ELF headers - which is what I wrote code to do[3]. The problem that > remains is determining the value of RLIMIT_CORE. (This is used to > determine whether the user wants a normal corefile, thus retaining > normal core dump behavior). > > As I understand it, getrlimit() won't return the correct values while > dumping to a pipe. So we need to pass the original RLIMIT_CORE to the > userspace helper somehow. It seems sensible to pass arguments to a > userspace program by using argv[]. So there we are. yup. The changelog should clearly document this new kernel/userspace interface, please. Things like what the argv format will be, which args are optional, etc. > There's probably many other uses for this stuff but that's the specific > one we're targeting. Does that make sense? If there's an easier way to > get the original RLIMIT_CORE from inside the crash handler, I'd love to > hear it. > I'm still emerging from the "what the heck is this" state ;) You need to tell us these things... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
